Hm. I used to do competitive air rifle shooting (fwiw top five in the nation at the time), and this experiment comes close to the sort of training that I would

Hm. I used to do competitive air rifle shooting (fwiw top five in the nation at the time), and this experiment comes close to the sort of training that I would do with my coach. He would act as a spotter and after every single shot, would ask me where my shot was (eg, 9pt at 4o'clock). We did this probably 300 times in the course of my training. Despite the "jitter", it was something that could eventually be done with surprising consistency after a while of training this way. It would be a completely different matter if the training was done on a new shooter (who were never, ever good when they first start). The training was also complete ineffective if I had caffeine, or wasn't in the right mood. My guessing ability would then effectively match what was seen in this test. I'm not sure how this test would have proven anything, especially with such a small sample size. As another poster mentioned, this very much sounds like a test for sensory motor latency, which is absolutely a nontrivial thing for this sort of test. If the test you described was done against trained shooters, I'd imagine the conclusion would likely be the opposite.